1. Field of the Invention
The invention relates to a power supply device to detect zero cross timings of an AC voltage supplied by an alternative-current (hereinafter, referred to as “AC”) power source and convert the AC into a direct current (hereinafter, referred to as DC) based on the zero cross timings thereby outputting a predetermined DC voltage and relates to an image formation apparatus having the power supply device.
2. Description of Related Art
A conventional image formation apparatus such as a copy machine, a printer, or a facsimile machine (hereinafter, referred to as “FAX”) executes an electric power control with a switching element such as triac, upon driving a heater in a fixation device or the like using an AC power source. The electric power control is executed based on a zero cross signal, which indicates zero cross points of a half-wave of the AC power source wave, as the basis for a timing to turn on the switching element (for example, Japanese Patent Application Laid-Open No. 2004-40913).